Metsulfuron-methyl is a residual sulfonylurea compound used as a selective pre- and postemergence herbicide for broadleaf weeds and some annual grasses. It is a systemic compound with foliar and soil activity, and it works rapidly after it is taken up by the plant. Its mode of action is by inhibiting cell division in the shoots and roots of the plant, and it is biologically active at low use rates. The most common uses of metsulfuron-methyl include wheat, barley, rye, and pastures. It can be used with other foliar herbicides, and is typically applied on non-crop areas at 0.005-0.160 pounds active ingredient/acre. It is commercially available in the form of dry flowable formulations.
Metsulfuron-methyl has residual activity in soils, it is necessary to allow ample time for the chemical to break down before planting certain crops. Metsulfuron-methyl herbicides should not be used on ryegrass or on pastures containing alfalfa or clovers